U.S. patent application number 17/169750 was filed with the patent office on 2021-08-12 for solid oxide fuel cell frame assembly.
This patent application is currently assigned to PHILLIPS 66 COMPANY. The applicant listed for this patent is PHILLIPS 66 COMPANY. Invention is credited to Mark J. Jensen, Mingfei Liu, Ying Liu.
Application Number | 20210249668 17/169750 |
Document ID | / |
Family ID | 1000005407176 |
Filed Date | 2021-08-12 |
United States Patent
Application |
20210249668 |
Kind Code |
A1 |
Liu; Mingfei ; et
al. |
August 12, 2021 |
SOLID OXIDE FUEL CELL FRAME ASSEMBLY
Abstract
A metal frame for sealing a solid oxide fuel cell. The metal
frame comprises both a metal top frame positioned on top of a
middle frame and a metal bottom frame that is positioned below a
middle frame.
Inventors: |
Liu; Mingfei; (Bartlesville,
OK) ; Liu; Ying; (Bartlesville, OK) ; Jensen;
Mark J.; (Bartlesville, OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PHILLIPS 66 COMPANY |
HOUSTON |
TX |
US |
|
|
Assignee: |
PHILLIPS 66 COMPANY
HOUSTON
TX
|
Family ID: |
1000005407176 |
Appl. No.: |
17/169750 |
Filed: |
February 8, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62972898 |
Feb 11, 2020 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M 8/0282 20130101;
H01M 8/0273 20130101; H01M 2008/1293 20130101 |
International
Class: |
H01M 8/0273 20060101
H01M008/0273; H01M 8/0282 20060101 H01M008/0282 |
Claims
1. A metal frame for sealing solid oxide fuel cells comprising: a
metal top frame positioned on top of a middle frame; and a metal
bottom frame positioned below a middle frame.
2. The metal frame of claim 1, wherein a top glass seal is situated
between the metal top frame and the middle frame.
3. The metal frame of claim 1, wherein a bottom glass seal is
situated between the metal bottom frame and the middle frame.
4. The metal frame of claim 1, wherein a solid oxide fuel cell is
situated below the metal top frame, above the metal bottom frame,
and inside the middle frame.
5. The metal frame of claim 4, wherein the thickness of the metal
middle frame is identical to the thickness of the middle frame.
6. The metal frame of claim 1, wherein the thickness of the metal
top frame ranges from about 0.1 mm to about 2 mm. The metal frame
of claim 1, wherein the thickness of the metal bottom frame ranges
from about 0.1 mm to about 2 mm.
8. The metal frame of claim 1, wherein the thickness of the middle
frame ranges from about 0.1 mm to about 2 mm.
9. The metal frame of claim 1, wherein the metal top frame, the
metal middle frame, and the metal bottom frame are brazed
together.
10. The metal frame of claim 1, wherein the middle frame is
ceramic.
11. The metal frame of claim 1, wherein the middle frame is
metal.
12. A metal frame for sealing solid oxide fuel cells comprising: a
metal top frame positioned above and connected to a top glass seal;
the top glass seal positioned above and connected to a metal middle
frame; the metal middle frame positioned above and connected to a
bottom glass seal, wherein the metal middle frame has a hole within
the center sized to fit a solid oxide fuel cell; the bottom glass
seal positioned above and connected to the metal bottom frame; and
the solid oxide fuel cell positioned below the top glass seal,
above the bottom glass seal, and situated within the metal middle
frame.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a non-provisional application which
claims the benefit of and priority to U.S. Provisional Application
Ser. No. 62/972,898 filed Feb. 11, 2020, entitled "Solid Oxide Fuel
Cell Frame Assembly," which is hereby incorporated by reference in
its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] None.
FIELD OF THE INVENTION
[0003] This invention relates to a solid oxide fuel cell frame
assembly.
BACKGROUND OF THE INVENTION
[0004] Solid oxide fuel cells (SOFC) have been the subject of
considerable research in recent years. A typical SOFC comprises an
electrolyte layer sandwiched between a cathode layer and an anode
layer. In a conventional design, multiple individual fuel cells are
arranged in a stack such that gas-tight seals are needed along the
edges of each cell on both air and fuel sides. The durability of
each seal is often limited due to the high temperatures and the
reducing and oxidizing gases present during fuel cell
operation.
[0005] Solid oxide fuel cells can undergo large thermal cycling and
large thermal gradients, inducing thermal stresses in the fuel cell
stack components. Seal failure can occur as a result of
deterioration, fracture or delamination of a seal material. Such
failure can be detrimental, resulting in the loss of electrical
current, damage to fuel cell components, and the escape and/or
mixing of reactant gases.
[0006] Thus, there is a need to address seal failure and other
shortcomings associated with conventional seals and methods for
sealing SOFCs.
BRIEF SUMMARY OF THE DISCLOSURE
[0007] This embodiment presents a metal frame for sealing a solid
oxide fuel cell. The metal frame comprises both a metal top frame
positioned on top of a middle frame and a metal bottom frame that
is positioned below a middle frame.
[0008] In yet another embodiment, a metal frame for sealing a solid
oxide fuel cell is described. In this embodiment, a metal frame is
positioned above and connected to a top glass seal. The top glass
seal is positioned above and connected to a metal middle frame. The
metal middle frame is positioned above and connected to a bottom
glass seal. The bottom glass seal is positioned above and connected
to a metal bottom frame.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] A more complete understanding of the present invention and
benefits thereof may be acquired by referring to the follow
description taken in conjunction with the accompanying drawings in
which:
[0010] FIG. 1 depicts an embodiment of the novel SOFC with metal
frame.
[0011] FIG. 2 depicts a SOFC sealed on a conventional single-piece
frame.
[0012] FIG. 3 depicts a SOFC sealed on a tri-layer metal frame
assembly
[0013] FIG. 4 depicts electrochemical performance of the new SOFC
metal frame assembly
[0014] FIG. 5 depicts comparative cell performance at 600.degree.
C., 650.degree. C., and 700.degree. C.
[0015] FIG. 6 depicts cell voltages measured under 200 mA/cm.sup.2
current at 600.degree. C.
DETAILED DESCRIPTION
[0016] Turning now to the detailed description of the preferred
arrangement or arrangements of the present invention, it should be
understood that the inventive features and concepts may be
manifested in other arrangements and that the scope of the
invention is not limited to the embodiments described or
illustrated. The scope of the invention is intended only to be
limited by the scope of the claims that follow.
[0017] As briefly introduced above, the present embodiment provides
a metal frame for sealing a solid oxide fuel cell (SOFC). The frame
comprises both a metal top frame positioned on top of a middle
frame and a metal bottom frame that is positioned below a middle
frame.
[0018] FIG. 1 depicts a side view of the embodiment, wherein the
SOFC 2 is enclosed with a tri-layer metal frame to avoid thermal
stress. The metal top frame 4 is positioned on top of the middle
frame 6, which is positioned on top of the metal bottom frame 8. To
avoid direct contact between the metal frame and the SOFC, glass
seals 10 can be disposed between the metal top frame and the middle
frame, the middle frame and the metal bottom frame, the middle
frame and the SOFC, the metal top frame and the SOFC, and the SOFC
and the metal bottom frame.
[0019] In one embodiment the metal top frame, the middle frame, and
the metal bottom frame can be made all out of the same material. In
an alternate embodiment, the metal top frame and the metal bottom
frame are made out of the same or different material while the
middle frame can be made out of a metal different from the metal
top frame and the metal bottom frame. In yet another embodiment,
the metal top frame and the metal bottom frame are made out of the
same or different material while the middle frame can be made out
of a non-metallic material.
[0020] Non-limiting examples of metal materials that the metal top
frame, the metal bottom frame and the middle frame can be made out
of include: stainless steels, carbon steels, nickel, copper, brass,
superalloys, silver, chromium alloys, molybdenum, and titanium.
[0021] Non-limiting examples of non-metal material that the middle
frame can be made out of include: metal oxides, metal carbides,
metal borides, glass, silicon, and fibers.
[0022] The thickness of the metal top frame, the metal bottom
frame, and the middle frame can be identical or not identical to
each other. In a non-limiting example, the thickness of each frame
can range from about 0.1 mm to about 2 mm.
[0023] The SOFC that can be used with this novel frame can be any
conventionally known SOFC device. Examples of SOFC's that can be
made include an anode, electrolyte, or cathode supported planar
cell.
[0024] In one non-limiting example, the method of forming the SOFC
frame assembly begins by first forming the metal frames, the glass
seals and the SOFC. The method then begins by applying the glass
seal on the metal bottom frame. The middle frame is then disposed
on top of the glass seal of the metal bottom frame. A SOFC is then
placed in the center of the middle frame on top of the glass seal
and a separate glass seal is applied around the SOFC to ensure that
the SOFC is not in direct contact with the middle frame. Another
glass seal is then placed on the surface of the middle frame
followed by the top metal frame to form a completed cell assembly.
This cell assembly is then transferred to a furnace and compressed.
The entire assembly is then annealed at a high temperature to
achieve a gas tight seal. By forming the cell assembly in such a
manner only a single heat cycle/annealing steps is necessary and
separate steps to soften the glass seal are not necessary. It is
theorized by exposing the cell assembly to only one high temperate
heat cycle there will be less curvature and less cell cracking of
the SOFC. Shown in FIG. 2 is an SOFC sealed on a conventional
single-piece metal frame. Shown in FIG. 3 is another SOFC mounted
on a three-layer metal frame. To build the three-layer metal frame
assembly, a thin glass coating was applied to a 0.15 mm thick SS430
metal bottom frame by screen-printing and then dried in oven at
90.degree. C. A 0.5 mm thick SS430 middle frame was added on top of
the glass coated bottom frame. An SOFC was then placed at the
center of the glass coated bottom frame and glass paste was applied
between the middle frame and the cell. A thin glass coating was
applied to a 0.15 mm thick SS430 metal top frame which was then
placed on top. Finally, the cell-frame assembly was annealed at
850.degree. C. for 1 h. The resulting cell-frame assembly was flat
and free of thermal stress. In contrast, the SOFC sealed on the
conventional single-piece frame structure was significantly curved
and the fuel cell was detached from the metal frame at four corners
after cooling to room temperature.
[0025] The conventional cell-frame assembly was not able to be
tested for electrochemical performance due to the severe gas
leakage at the four corners of the cell. The current-voltage and
current-power density curves of a short stack containing three
metal frame assemblies are shown in FIG. 4. The cells showed
excellent performance, i.e., 172, 225, and 259 mW/cm.sup.2 at 0.8V
in hydrogen at 600, 650, and 700.degree. C., respectively as shown
in the 3-cell stack test in FIG. 5. In FIG. 6 a cell with the novel
metal frame assembly was tested under 200 mA/cm.sup.2 current at
600.degree. C. This cell assembly ran for over 500 hours and showed
less than a 2%/1000 degradation.
[0026] In closing, it should be noted that the discussion of any
reference is not an admission that it is prior art to the present
invention, especially any reference that may have a publication
date after the priority date of this application. At the same time,
each and every claim below is hereby incorporated into this
detailed description or specification as an additional embodiment
of the present invention.
[0027] Although the systems and processes described herein have
been described in detail, it should be understood that various
changes, substitutions, and alterations can be made without
departing from the spirit and scope of the invention as defined by
the following claims. Those skilled in the art may be able to study
the preferred embodiments and identify other ways to practice the
invention that are not exactly as described herein. It is the
intent of the inventors that variations and equivalents of the
invention are within the scope of the claims while the description,
abstract and drawings are not to be used to limit the scope of the
invention. The invention is specifically intended to be as broad as
the claims below and their equivalents.
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